Field
The present disclosure relates to a printer performing desired printing on a print-receiving medium.
Description of the Related Art
A printer performing desired printing on a print-receiving medium has hitherto been known. In this printer (an ink-jet head printer), a printing head (a discharge head) performs printing on a print-receiving medium (sheet) that is fed by a feeder (feeding rollers), to form a printed print-receiving medium (printed matter). At that time, the print-receiving medium is fed by a driving force generated by an energized motor. The positive electrode and negative electrode of the motor are short-circuited with the motor deenergized, so that the motor is braked (short braked) so as to fix the position of the print-receiving medium.
The motor (esp. a DC motor) used as a driving source as the above in the printer has a property that the motor slightly continues to rotate by inertia before rotation stops, even if deenergized while being rotationally driven through energization. At that time, since the amount of inertia slightly differs due to printer-specific loads or parts variations, the amount of feeding caused by the inertial rotation varies, with the result that the generated printed matter may have undesirable variations, i.e. a relatively large rear margin (margin appearing further upstream of the upstream end in the transport direction of a print area where print is formed) in some cases or, conversely, a small rear margin in other cases.
In order to avoid this, it is conceivable to apply the prior art braking technique short-circuiting the positive electrode and negative electrode of the motor at the time of the inertial rotation as described above so that a relatively small constant rear margin is obtained (so that the feeding is braked to a specified length for accurate positioning).
However, this case also involves the following problem. That is, in the case of performing the short-circuit braking at the time of the inertial rotation in the above manner, the ambient temperature may affect it. More specifically, when the ambient temperature is relatively high, the entire driving system has a relatively small load (i.e. feeding resistance) during the transport of the print-receiving medium, whereas when the ambient temperature is relatively low, the entire driving system has a large load (feeding resistance) during the transport of the print-receiving medium. In consequence, if certain braking is applied regardless of the temperature, the transport may not be able to be stopped at an expected timing when the ambient temperature is relatively high, resulting in an elongated rear margin. On the contrary, when the ambient temperature is relatively low, the transport may be stopped at an earlier timing than the expected timing, resulting in a shortened rear margin.